Advice re creasing? Sewing Machines Parts and Sales in Los Angeles

I've made some superhero capes and masks for my son and his friend for Christmas. The outer layer is a blue quilting cotton fabric and the lining is a red cheapo man-made satin. The capes look great but i'm finding that I press them and then even the slightest fold is leaving a really obvious crease. I know this is probably because the fabric is pretty cheap. Does anyone know, is there anything I can wash it with or treat it with which will help with the creasing? Thanks in advance.